/* Copyright 2019 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/
#include <gtest/gtest.h>
#include "flatbuffers/flexbuffers.h"  // TF:flatbuffers
#include "tensorflow/lite/interpreter.h"
#include "tensorflow/lite/kernels/kernel_util.h"
#include "tensorflow/lite/kernels/register.h"
#include "tensorflow/lite/kernels/subgraph_test_util.h"
#include "tensorflow/lite/kernels/test_util.h"
#include "tensorflow/lite/model.h"

namespace tflite {

using subgraph_test_util::CheckIntTensor;
using subgraph_test_util::ControlFlowOpTest;
using subgraph_test_util::FillIntTensor;

namespace {

class WhileTest : public ControlFlowOpTest {};

// The test builds a model that produces the i-th number of
// triangular number sequence.
//
// TODO(ycling): Consider to improve this test case by adding a
// concat into the body subgraph.
TEST_F(WhileTest, TestTriangularNumberSequence) {
  const std::vector<int> expected = {1, 3, 6, 10, 15, 21, 28};
  for (int i = 0; i < expected.size(); ++i) {
    interpreter_.reset(new Interpreter);
    interpreter_->AddSubgraphs(2);
    builder_->BuildLessEqualCondSubgraph(interpreter_->subgraph(1), i);
    builder_->BuildAccumulateLoopBodySubgraph(interpreter_->subgraph(2));
    builder_->BuildWhileSubgraph(&interpreter_->primary_subgraph());

    interpreter_->ResizeInputTensor(interpreter_->inputs()[0], {1});
    interpreter_->ResizeInputTensor(interpreter_->inputs()[1], {1});
    ASSERT_EQ(interpreter_->AllocateTensors(), kTfLiteOk);
    FillIntTensor(interpreter_->tensor(interpreter_->inputs()[0]), {1});
    FillIntTensor(interpreter_->tensor(interpreter_->inputs()[1]), {1});

    ASSERT_EQ(interpreter_->Invoke(), kTfLiteOk);
    TfLiteTensor* output1 = interpreter_->tensor(interpreter_->outputs()[0]);
    CheckIntTensor(output1, {1}, {i + 1});
    TfLiteTensor* output2 = interpreter_->tensor(interpreter_->outputs()[1]);
    CheckIntTensor(output2, {1}, {expected[i]});
  }
}

// This requires dynamic sized subgraphs and it's not supported right now.
// TODO(ycling): Support dynamic sized subgraphs.
TEST_F(WhileTest, TestPadLoop) {
  interpreter_.reset(new Interpreter);
  interpreter_->AddSubgraphs(2);
  builder_->BuildLessEqualCondSubgraph(interpreter_->subgraph(1), 3);
  builder_->BuildPadLoopBodySubgraph(interpreter_->subgraph(2), {1, 2});
  builder_->BuildWhileSubgraph(&interpreter_->primary_subgraph());

  interpreter_->ResizeInputTensor(interpreter_->inputs()[0], {1});
  interpreter_->ResizeInputTensor(interpreter_->inputs()[1], {2});
  // This is not supported yet. The test ensures thatit doesn't crash and raises
  // an error properly.
  ASSERT_EQ(interpreter_->AllocateTensors(), kTfLiteOk);

  FillIntTensor(interpreter_->tensor(interpreter_->inputs()[0]), {1});
  FillIntTensor(interpreter_->tensor(interpreter_->inputs()[1]), {5, 7});

  ASSERT_EQ(interpreter_->Invoke(), kTfLiteOk);
  TfLiteTensor* output1 = interpreter_->tensor(interpreter_->outputs()[0]);
  CheckIntTensor(output1, {1}, {4});
  TfLiteTensor* output2 = interpreter_->tensor(interpreter_->outputs()[1]);
  CheckIntTensor(output2, {11}, {0, 0, 0, 5, 7, 0, 0, 0, 0, 0, 0});
}

}  // namespace
}  // namespace tflite

int main(int argc, char** argv) {
  ::tflite::LogToStderr();
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}
